If you practice or teach karate as a means of self-defence, then I think it's crucial that you make a conscious effort to explore common traditional practices for aspects that are counter-productive to this goal. I'm not saying that we should eliminate these altogether (as they may provide other values), but it's important I feel that we are proactively mindful of where they may contextually sit.
One of the issues with traditional karate practice in terms of training for self-defence is that of environment. In reality, the application of any self-defence effort will involve interaction with either a real or potential violent threat to the safety of you, a friend or loved one. And the environment by which this interaction takes place may be totally unpredictable and critical to the outcome. Furthermore, that environment is likely to be in direct contrast to that of the dojo.
Here's an excerpt from My Book on the application of Naihanchi Kata for self-defence that discusses environmental considerations...